Manufacture of motor fuels



Aug. 8, 1944.

FRACTIONATOR T LE ROY G. STORY ,355,339

MANUFACTURE OF MOTOR FUELS Original Filed March 21, 1939 SEPARA REACTORLEROY G. STORY NVENTOR HIS A'l fTaRNEY Patente d Aug. 8, 1944MANUFACTURE or MOTOR runs Le Roy G. Story, Chicago, Ill., assignor toThe Texas Company, New York, N. Y., a corporation of Delaware Originalapplication 261M140v Divided an 1943, Serial No. 483,741

12 Claims. (Cl. 260-683.!)

This invention relates to the manufacture of motor fuels and has to domore particularly with the production ofhigh anti-knock hydrocarbonsfrom olefins and paraflins.

This is a division of my copending application, Serial No. 263,114,filed March 21, 1939.

In accordance with the invention, paraffins and oleflns, includingnormal and iso-olefins and normal and. isoparafdns, are subjected tothe' action of a catalyst in the presence of hydrogen whereby highanti-knock, chiefly saturated, branch chain hydrocarbons within thegasoline boiling point range are formed.

An object of the present invention is to obtain alkylation of normal orisoparaifins with Another object of the invention is to obtainpolymerization and hydrogenation of a portion of the olefins in anolefin and paraffin mixture, and to obtain alkylation of paraflins withanother portion of the oleflns.

Another object of the invention is to. control and regulate the amountof polymerization and alkylation whereby an increased amount of desiredhigh anti-knock hydrocarbons is formed.

A further object of the invention is to prevent undesirable sidereactions and increase the yield of desired hydrocarbons.

A Zurther object of the invention is to prevent catalyst deteriorationwhereby the life of the catalyst is substantially increased.

A further object of the invention is to provide means whereby parafflnand olefin hydrocarbon mixtures containing a relati ely large proportionof olefins may be success ully con-,.

verted into large yields of saturated branch chain hydrocarbons.

It has been known heretofore that isoparaffins may be alkylated witholefins in the presence of catalysts, such as sulfuric acid or aluminumchloride, providing a high ratio of isoparaflins to oleflnsis'maintained in the reaction mixture.

It has also been proposed to alkylate normal parafhns with olefins inthe presence of a catalyst such as aluminum halide and hydrogen halideby using a'substantial excess of normal parafnns in the reactionmixture. In these operations, however, side reactions and deteriorationof the catalyst occurs, particularly if a high ratio of parailins tooleiins is not maintained. w

It has now been found that it is advantageous to carry out reactionsinvolving alkylation in the presence of hydrogen or a hydrogen-producingmaterial or a hydrogen-containing gas.

March 21, 1939, Serial No.

(i this application April 20,

The amount of hydrogen may vary considera hydrogen pressure of 50, 1000or 3000 pounds may be ably, for example, 100, 150, 300, 500,

used. It is preierabletousea hydrogen pressure of about 50 to 500 or1000 pounds.- Hydro genation may occur or the hydrogen may functionprimarily to control the course of the reactions and increase the lifeof the catalyst.

The fcatalysts contemplated are sulfuric acid of about to and preferablyabout 94 to 98% H2504; a metallic halide alone, or preferably with ahydrogen halide, such as AlCls or BF; and H Cl or HF; a metallic halideand a metal, with or without a hydrogen halide, such,

as A1013, Al, and HCl, or BFa, HF andNi; liquid hydrogen fluoride; andmixed metallic halides such as sodium aluminum chloride. A metal, orcompound of a metal, such as an oxide or sulfide of a metal of group VI,particularly chromium, molybdenum or tungsten, may also be used.Mixtures oI-the above catalysts are contemplated, 'whereby combined'hydrogenation and alkylation, or combined alkylation, polymerizationand hydrogenation, are obtained.

Thus, AlCh and/or the compounds of metals of group VI are intended; forexample, aluminum chloride and compounds, such as chromium, zirconium ormolybdenum oxides and sulfides.

- It'is to be understood that whenever a metallic halide is specifiedthe corresponding hydrogen halide may also be used.

The temperatures of operation will depend somwhat upon; the materialstreated, the catalyst, and the nature of the reaction involved.

Broadly, temperatures of about -10 to 100 200, or 250 C. or over arecontemplated, although ordinarily temperatures of 0 to 75 C. aredesirable.

The hydrocarbons to be treated may comprise isoparaiilnaoleiins andnormal paraffins, either gaseous or liquid. Low-boiling parafiins andolefins, such as normally gaseous hydrocarbons of two to-flve carbonatoms, for example, cracking still gases, are suitable, althoughgasoline hydrocarbons or heavier, either straightrun orcracked, arecontemplated. Some of the more specific applications of the inventionwill now be discussed.

The alkylation of normal paraflins with oleflns has not been practicalheretofore because more drastic conditions and aunore active catalystthan for the alkylation of isoparaiiins are desirable. However. whensuch conditions are used even in the presence of a large excess ofnormal paraiilns, side reactions and catalyst deterioration aretroublesome. When using considerable pressure of hydrogen, more drasticconditions may be used with success whereby polymerization, splittingand catalyst deterioration are substantially prevented.

The alkylation of higher'boiling paraflins and olefins, such as occursin cracked gasoline, has

been difiicult to carry out because of large catalyst and polymerizationlosses. For example, the alkylation of the olefins in 'a crackedgasoline with isoparafiins usually causes excessive catalystconsumption, thereby rendering'the operation impractical. A substantialpressure of hydrogen largely eliminates such dlfiiculties.

It is often desirable to alkylate a C4 fraction from cracking stillscontaining both normal and isobutylene, and normal and isobutane, butbecause the oleflns are in excess, it has been customary to add anexcess of extraneous isobutane. By introducinghydrogen, such a fractionmay be alkylated without extraneous isobutane, particu larly when usingactive catalysts, such as aluminum chloride or mixed metal chlorides,and good yields of alkylate apparently from alkylating both normal andisoparafiins, and a substantially saturated product, are obtained.

Heretofore it has been customary to selectively polymerize isobutylenein a cracking still gas to di-isobutylene and hydrogenate the latter toiso-octane. The normal butenesmay then be alkylated with isobutane inthe presence of an alkylation catalyst using an excess of isobutane. Theproducts may then be blended to obtain a high octane product. Accordingto the present invention, thev above operations may be carried out inone step instead of two by using hydrogen and a suitable catalyst. Forexample, a C4 cracked gas containing about 30% butylenes, isobutane and55% normal butane may be converted substantially entirely into gasolineof high anti-knock value. A product approaching in anti-knock value thatproduced by the twostep process may be obtained, indicating that thereaction is much more selective in producing isoparafins of highanti-knock value.

In the latter example, it is advantageous to operate whereby theisobutylene is converted mainly into iso-octane, while the normalbutenes are converted into mixed isoparaflins which may have a widerboiling range approaching thatof gasoline. For such a result, it may bedesirable to use a mixture of catalysts which may produce at least somehydrogenation and polymerization, such'as aluminum chloride and/orcompounds of metals of group VI specified. While the reactions arenot'fullyv understood, possible reactions are selective polymerizationand hydrogenation of isobutylenes to hydrogenated di-isobutylenes oriso-octanes, selective alkylation of isobutane with isobutylene toproduce iso-oci tanes, polymerization or cross-polymerization of v theisobutylenes and normal butylenes to form polymers which arehydrogenated and/or selectively alkylated by the isobutane. Regardlessof the nature of the'reaction, the iso-octanecontent of the gasolinefraction may be appreciably increased and a high octane productobtained.

At the higher alkylation temperatures specilied above, such as 150 C.and above, the mentioned metal oxides and sulfides of group VI are knownto have appreciable hydrogenation activity; and thejcontacting of theparaifins and olefins in the presence of an alkylation catalyst and ahydrogenation catalyst that has appreciable hydrogenation activity atthe said alky Referring to the drawing, the hydrocarbons,

may be introduced into the system through branch line I, whichcommunicates with the main line 2 leading toa reaction chamber 3.

Hydrogen may be introduced through the branch line 5 which alsocommunicates with the line 2. While one line is shown for introducingthe hydrocarbons, it is to be understood that any number of lines may beused in case it is desirable to separately inject the olefins andisoparaflins. Also, aseparate line forinjecting the hydrogen may beused, if desired. In the reactor 3,the Y hydrocarbons and hydrogen areintimately contacted with the catalyst introduced through the line I.The reactor may be provided with a suitable agitator or other means ofcontact, whereby the catalyst, hydrogen and hydrocarbons are intimatelycontacted and a suitable reaction time provided.

The products are conducted from the reactor 3 through the line 8 to aseparator I0. Any portion of the products withdrawn through line 8 maybe recycled to the reactor through the line I l by the pump I2. Thelines 8, II and pump l2 constitute an internal recycle stream into whichthe hydrocarbons and hydrogen from lines I, 5 and 2 are preferablyinjected. It is desirable to maintain a relatively high ratio ofproducts recycled internally to the fresh charge introduced through theline 2.

In the separator I0 hydrocarbons separate from the catalyst whichcollects in the lower portion of the separator. The separated catalystis withdrawn through the line M and may be forced by thepump I5 throughthe line 1 to the reactor 3. Any portion of the separated catalyst maybe withdrawn from the system through the line I6. Fresh make-up catalystmay be charged to the system through the line I8 which communicates withthe line 1.

The hydrocarbons collecting in the upper portion of the separator ID arewithdrawn through the line 20. Any portion or all of the hydrocarbonsmay be returned to the reactor 3 through the branch line 2|. Theremainder ofthe hydro.- carbons is conducted through the branch line 22to a fractionator 24, which is preferably main tained under sufficientpressure to maintain the hydrocarbons in the liquid phase. Provision ismade whereby hydrogen may be withdrawn from the top of the fractionatorthrough the line 25 and discharged from the system through the In thestabilizer the light hydrocarbons, comprising mainly isobutane, whichare undesirable in' the alkylate, are separated and released from thetop of the stabilizer through the line 34. Any portion or all of thegases may be recycled through the branch line 35, pump 38 and line 38 tothe internal recycle stream in line II. The stabilized alkylate iswithdrawn from the stabilizer through the line 40.

The feature of catalytic isoparaflin-olefin alkylation in the presenceof an alkylation catalyst at comparatively low or mild temperatures, andwith added hydrogen to maintain a substantial hydrogen pressure withinthe alkylation reactor, is claimed in my said parent application, SerialNo. 263,114. The feature of alkylating parafilns with olefins underalkylating conditions in the presence of an alkylation catalyst and ahydrogenation catalyst that has appreciable hydrogenation activity atsaid alkylating conditions is claimed in the present divisionalapplication.

Obviously many modifications and variations oi the invention, ashereinbefore set forth, may be made without departing from the spiritand scope thereof, and therefore only such limitations should be imposedas are indicated in the appended claims.

I claim:

1. The process of alkylating paraflins with olefins wherein paraflinsand olefins are charged to the alkylation reaction which comprisescontacting the paramns and olefins under alkylating conditions in thepresence of an alkylation catalyst and a hydrogenation catalyst that hasappreciable hydrogenation activity at said alkylating conditions.

2. The process of manufacturing high octane motor fuel by alkylatingnormally gaseous paraffins with normally gaseous olefins whereinparaffins and oleflns are charged to the alkylation reaction whichcomprises contacting the parafllns and olefins under alkylatingconditions in the presence of an alkylation catalyst and a hydrogenationcatalyst that has appreciable hydrogenation activity under saidalkylating conditions.

3. The process of alkylating paraflins with 01eiins whereinparafiins andoleflns are charged to the alkylation reaction which comprisescontactafllns with normally gaseous olefins wherein paraifins andoleiins are charged to the alkylation reaction which comprisescontacting the paraflins and olefins under alkylating conditions in thepresence of an alkylation catalyst and a hy drogenation catalyst thathas appreciable hydrogenation activity under said alkylating conditions,and in the presence of extraneouslyadded hydrogen.

5. The process according to claim 1, wherein the alkylation catalystcomprises a metallic halide.

6. The process according to claim 1, wherein the alkylation catalystcomprises mixed metallic halides.

7. The process according to claim 1, wherein the hydrogenation catalystis selected from the group consisting of a metal of Group VI of theperiodic table of elements, and an oxide or sulfide of such a metal.

8. The process according to claim 1, wherein the hydrogenation catalystcomprises an'oxide of chromium.

9. The process of manufacturing high octane motor fuel by alkylatingparaflins with olefins, which comprises contacting the paraflins andolefins at an elevated temperature above about 150 C. and under asubstantial superatmospheric pressure under alkylating conditions in thepresence of an alkylation catalyst and a hydrogenation catalyst that hasappreciable hydrogenamotor fuel by alkylatingnormally gaseous paring theparamnsand olefins under alkylating afllns with normally gaseousolefins, which comprises contacting the normally gaseous paraffins withnormally gaseous oleflns at an elevated temperature above about C. andunder a substantial superatmospheric pressure of added hydrogen underalkylating conditions in the presence of an alkylation catalyst and ahydrogenating catalyst that has appreciable hydrogenating activity atsaid alkylating conditions.

11. The process according to claim 10, wherein the alkylation catalystcomprises a metallic halide, and the hydrogenation catalyst comprises anoxide of a metal of group VI of the periodic table of elements.

12. The process according to claim 10, wherein the alkylation catalystcomprises a metallic halide, and the hydrogenation catalyst comprises anoxide of chromium.

LE ROY G. STORY.

